Telecommunication systems include components that are able to perform various operations on voice and/or data communications carried within such systems. For example, a network based on the Global System for Mobile Communications (GSM) standard may utilize a network element such as a transcoder rate adaption unit (TRAU) to handle the use of different codecs and rates. A TRAU may handle transcoding to convert information between two coding schemes, and may provide rate adaptation to handle the use of eight, sixteen, or thirty-two kbps rather than a higher rate such as sixty-four kbps so that networks or network elements using different codecs and rates can communicate.
To enable control over the configuration of TRAUs for mobile to mobile traffic, Tandem Free Operation (TFO) functionality has been developed. When TFO is deployed, call setup is performed as normal, including the allocation across the network(s) of a 64 kbps channel and insertion of the TRAU in the access and terminating networks. As specified by TFO, the TRAUs will attempt to communicate with one another utilizing in-band signaling over the 64 kbps bearer channel. If communication is successful and the mobile stations support compatible codecs, the transcoding in the access network is disabled, allowing compressed speech to be transported across the mobile network. However, current TFO implementations have limitations that inhibit their usefulness.
Accordingly, an improved method and system for packet-based TFO are needed.